mineral

Amethyst (rough purple quartz)

Quartz, SiO₂; purple color from trace iron and natural irradiation

AI-generated identification · may be incorrect

Mohs hardness 7; purple to lavender, vitreous luster, trigonal crystal structure, no cleavage and conchoidal fracture. The specimen appears rough and partly worn; its exact quality cannot be determined from the image.

Identified October 3, 2026More mineral →

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Physical properties

Formation & geological history

Forms in silica-rich hydrothermal veins and gas cavities in volcanic rocks as quartz crystals grow from mineral-rich fluids. Amethyst deposits range from ancient to geologically recent, depending on the host rock.

Uses & applications

Used for jewelry, carvings, and mineral collecting; lower-grade material is also used decoratively.

Geological facts

Amethyst is the purple variety of quartz; heat can alter its color, sometimes producing citrine-like yellow tones.

Field identification & locations

Identify by purple color, glassy luster, and hardness sufficient to scratch glass; common sources include Brazil, Uruguay, Zambia, and other quartz-bearing regions. The image does not show diagnostic crystal faces, so identification is based mainly on color and appearance.